Over 30% of Americans are obese (body mass index [BMI] of 30 and above) and, as a result, they are at increased risk for a variety of serious obesity-related conditions such as type 2 diabetes, hypertension, sleep apnea and some types of cancer. Obesity is also associated with a diminished quality of life and impaired psychosocial functioning. Although standard behavioral treatment produces generally modest weight losses, there is great variability in treatment response, likely because standard treatments do not account for individual differences in the factors that contribute to weight control. Emotional eating (eating in response to emotional distress) has been identified as a likely a contributor to individual differences in body weight. The proposed research will develop and assess a novel weight loss treatment for obese emotional eaters, a previously untargeted group of obese individuals without binge eating disorder who respond to negative emotions by eating and, thus, are more vulnerable to difficulties with weight control. Eighty obese (BMI 30 - 45) emotional eaters will be randomized to one of two weight loss conditions: 1) an Enhanced behavioral treatment which combines standard behavioral treatment for obesity with skills for observing, tolerating and effectively managing and expressing negative emotions and decreasing ineffective responses to negative emotions (n=40) or 2) a Standard behavioral treatment (n=40). The primary specific aims are to examine between-group differences in (1) weight loss and (2) emotional eating at 12 weeks. Exploratory aims are to examine the feasibility of the novel Enhanced weight control intervention and investigate whether gender, negative affect, and stress moderate between-group differences in weight loss. Weekly group treatment will be conducted for a total of 12 weeks. Weight, emotional eating, negative affect, stress, and treatment acceptability will be evaluated at baseline and 12 weeks. This is the first study to develop and test a weight loss intervention for obese emotional eaters. Relevance: Obesity is a prevalent, serious, and refractory problem. There is significant variability in weight loss in response to standard behavioral treatment of obesity, likely due to individual factors such as emotional eating. This study will provide valuable information about the efficacy of a weight loss intervention for obese emotional eaters, and it will advance our understanding of individual factors related to weight loss. Findings from the proposed study have the potential to improve obesity treatment which, ultimately, may reduce the prevalence of obesity and its associated medical and psychological consequences.